Phase 1 Dose-Ranging Study of Ezatiostat Hydrochloride (Telintra®, TLK199 Tablets)in Combination With Lenalidomide (Revlimid®)in Patients With Non-Deletion(5q) Low to Intermediate-1 Risk Myelodysplastic Syndrome (MDS)

Inclusion Criteria:

- Histologic diagnosis of primary or de novo MDS using WHO classification

- Non-del(5q) low or Intermediate-1risk MDS

- ECOG performance status of 0-1

- Documented significant cytopenia for at least 2 months

- Must have discontinued growth factors (EPO, G-CSF, GM-CSF) for at least 21 days prior
to study entry

- All study participants must be registered into the mandatory RevAssist® program and
be willing and able to comply with the requirements of RevAssist®

- Females of childbearing potential should have two negative serum pregnancy tests with
a sensitivity of at least 50 mIU/mL. The first test should be performed within 10-14
days, and the second test within 24 hours of prescribing lenalidomide (prescriptions
must be filled within seven days)

Exclusion Criteria:

- Known hypersensitivity to Telintra™ (intravenous or oral)

- Known prior therapy with or hypersensitivity to thalidomide or lenalidomide

- Prior allogenic bone marrow transplant for MDS

- History or prior malignancy

- Except for treated carcinoma of uterine cervix, basal cell or squamous cell skin
cancer, or other cancers (e.g. breast, prostate) for which patient has been
disease-free for at least 3 years.

- MDS evolving from:

- A pre-existing myeloproliferative disorder

- An autoimmune disease

- Secondary to prior treatment with radiation or chemotherapy

- History of MDS IPSS score>1.0

- Pregnant or lactating women

- Leptomeningeal or leukemic meningitis

- Prior treatment with DNA methyltransferase inhibitors (DMTI) [e.g., azacitadine,
decitabine, etc.]